4.3.20, Copy/paste doesn't work with one-staff piano

I created a part for piano with one staff. The second staff was removed by context menu > staff > remove staff. After that cmd+c, cmd+v functions, and edit > copy, edit > paste don’t work. When you return the second staff all commands work.

Hi @Oleksa and welcome to the Forum.
For me it works.
If you can share your project (or a part of it) here, if would be useful to see what is happening.

Hi, @Christian_R I attached the file. It seems it works now in both cases. But I fighted with this all the previous day.
copy.dorico (623.4 KB)

Good to hear.
If this happens again you can post here the exact steps to reproduce the unwanted behavior.
(But for now it looks as the functions work as expected)